package com.hmdp.utils;

import cn.hutool.core.io.resource.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock {
    private String name;
    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString() + "-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;// LUA脚本

    static {//  静态代码块
        UNLOCK_SCRIPT = new DefaultRedisScript<>();//  创建脚本
        UNLOCK_SCRIPT.setLocation((Resource) new ClassPathResource("unlock.lua"));// 指定脚本位置
        UNLOCK_SCRIPT.setResultType(Long.class);//  返回结果类型
    }

    @Override
    public boolean tryLock(long timeoutSec) {
        //获取线程标识
        String threadId = ID_PREFIX + Thread.currentThread().getId() + "";
        //获取锁
        Boolean b = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name, threadId, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(b);
    }


    @Override
    public void unLock() {
        stringRedisTemplate.execute(UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX + Thread.currentThread().getId());
    }
//    @Override
//    public void unLock() {
//        String threadId = ID_PREFIX + Thread.currentThread().getId() + "";
//        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
//        if (threadId.equals(id)){
//            stringRedisTemplate.delete(KEY_PREFIX + name);
//        }
//    }
}
